A Highly Efficient Biocatalytic Conversion of Renewable Pectic Polysaccharide Biomass into Bioactive Oligogalacturonides

The quest for an efficient biodegradation of pectic polysaccharides into sustainable oligogalacturonide (OG) products for a recent bioactivity study and application is currently underway. This study reported highly efficient degradation of pectin into OGs (DP2–DP10) by a polygalacturonase (i.e., AnPG28A from Aspergillus niger). The activity of AnPG28A toward low-methoxyl pectin reached 42897 units/mL, and the protein concentration was 7.7 g/L after 96 h, the highest of the reported values. For further processing of commercial pectins to produce OGs, the physicochemical properties of different kinds of commercial pectins on the market were characterized. The preparation of high-purity OG standards (DP2–DP7) was achieved with polygalacturonic acid as a substrate by high-performance liquid chromatography, which helps the preparation of OG, its usage, and the study of its functional characteristics. Moreover, further OG production pilot experiments were performed on the basis of a response surface methodology. The OG yield was approximately 65% on the pilot scale. AnPG28A has many advantages, such as easy, inexpensive preparation, greenness, and excellent catalytic activity. The high yield and quality of OGs and the sustainability and eco-friendly process support the forthcoming commercialization of the biocatalytic transformation of pectin into high-value-added OGs.